Swivel joint coupling for lamp arms



l May 30,

, 15 lAA 3% ,Filed Feb. 9, 1966 J. WARSHAWSKY SWIVEL JOINT CO'UPLING FORLAMP ARMS I N VEN TOR.

f) noe/V675 I United States Patent() 3,322,886 SWIVEL JOINT CGUPLING FORLAMP ARMS Ierome Warshawsky, 3285'Bertha Drive,

` Baldwin, N.Y. 11510 Filed Feb. 9, 1966, Ser. No. 526,094 4 Claims.(Cl. 174-86) Thisinvention relates to electric wiring installation andfittings and more particularly is directed to an improved swivel jointcoupling for arms of lighting fixtures through which electric wiringextends. l n

Among the objects of the invention is to provide an improved swiveljoint coupling of the character described which shall comprise few andsimple parts for economical manufacture in low cost quantity production,which coupling shall -be readily installed as a means of articulationbetween armsl in a lighting fixture and have readily movable partsretained under preset spring pressure against accidental displacementfrom desired set positions, which shall facilitate wiring of thelighting fixture by permitting assembly of the coupling after suchwiring, which assembly shall require a minimum of time and skilled laborusing Simple hand tools, which coupling shall resist loosening orreduction of the preset spring pressure after repeated movement of thejoint, which shall Vbe neat in appearance, rugged in construction towithstand rough usage, and efficient and practical to a high degree.

Other objects of the invention will in part be obvious and in parthereinafter pointed out. Y

The invention accordingly consists of features of construction,combination of elements and arrangement of parts which will beexemplified in the constructions hereinafter disclosed, the scope of theapplication of which Will be indicated in the claims following.

In the accompanying drawing in which various illustrative embodiments ofthe invention are shown:

FIG. 1 is a perspective view of a swivel joint coupling constructed toembody the invention shown interconnecting a pair of arms of anelectrically wired lighting fixture for articulating relative movement.

FIG. 2 is a vertical sectionv of the coupling illustrated in FIG. lshowing the interior construction.

FIG. 3 is an exploded view of the parts of the coupling shown in FIGS. 1and 2.

FIGS. 4 and 5 are sectional views taken on lines 4-4 and 5 5respectively in FIG. 2.

FIG. 6 is a vertical section similar to FIG. 2, but removed from the armassembly, showing a modified form of `the invention.

Referring in detail to the drawing, 10 denotes an electrically wiredarticulating arm section of a lighting fixture incorporating swiveljoint coupling 11 constructed to embody the invention and shown tocomprise an anchor member 12, a rotary member 13, an axial retainingstud 14, a compression spring and a washer 16.

Anchor member 12 and rotary member 13, and axial stud 14 may `be made ofany suitable metal stock preferably brass, machined or otherwise formedas cylindrically shaped mating halves of and retaining means forcoupling 11, respectively. Anchor mem-ber 12 has a closed end wall 12bintegrally formed on the interior thereof with an axial boss 12c whichis drilled and tapped to provide interior threads 12d. Cylindrical sidewall 12a, upstanding from end wall 12b, may be formed with a threadedside opening 12e for receiving a threaded end of an arm A of thelighting fixture (not shown). The end of anchor member 12 opposite endWall 12b is open, the .rim edge of side wall 12a bein-g provided withsuitable means for rotatably seating Irotary member 13 thereon, here4shown as a rabbet 12,1".

Rotary member 13 has a cylindrical side wall 13a which is open atopposite ends but is formed with an interior 3,322,886 l Patented May30, 1967 lCC transverse wall 13b having a central opening 13e and aySide opening 13d located to span threaded opening 13e in side wall 13awhich receives an arm AA of the lighting fixture (not shown). The rimedge of one end of side wall V13a is provided with a complementary meansfor rotatably `engaging anchor member 12, here shown as complementaryrab-bet 13f. 'Ihe rim edge of the opposite end of side wall 13a isformed with an interior shoulder 13g for seating washer 16 therein.

Stud 14, having a slotted head 14e of enlarged crosssection engagingwasher 16, extends through central opening 13e of interior transversewall 13b and terminates in a threaded end 14a kfor engaging 1bossthreads 12d. Threader end 14a may be of reduced cross-section providingshoulder 14b for abutting axial boss 12e, the distance along stud 14between headf14c and shoulder 14b being accurately predetermined toinsure a slight clearance between washer 16 and interior shoulder 13gwhen shoulder 14b is locked tightly against axial yboss 12C.

.f Compression spring 15 acting between transverse wall A13b and washer16 exerts a friction pressure, that is, a

lbinding Iforce, between members 12 and 13 at the rabbet jointtherebetween, the compression properties of spring 15 being chosen tosatisfy minimum torque requirements for initiating relative angularmovement between articulated arms A and AA.

One of the features of the invention is the arrangement of stud 14whereby anchor member 12 and rotary member 13 may be assembled at thetime and place of the lighting fixture asernbly. Thus, anchor member 12and rotary member 13 are separately threaded onto arms A ,and AA,respectively. A leading end of electric wiring W maybe threaded througharm A to emerge from anchor member 12 and then inserted into the end ofarm AA which is secured in opening 13e and readily accessible throughthe open inner end of rotary member 13 and lateral opening 13d ininterior transverse wall 13b. Electric wiring W may then be pulledthrough the separated parts and the wirin-g of the lighting fixturecompleted in any well understood manner. Assembly of swivel jointcoupling 11 is readily accomplished Iby placing washer 16 and `spring 15on stud 14, seating rotary member 13 on anchor member 12, inserting stud14 through central opening 13C, and threading end 14a into boss 12C.Stud 14 may be tightened with a screwdriver.

The practical operation and utility of electrically wired arm section 10will now be apparent. The angular relation of arms A and AA, joined bycoupling 11, may be readily adjusted by application of forcetherebetween sufficient to overcome the friction at the rabbet jointexerted by spring 15. Referring to FIGS. 1 and 2, stud 14, whentightened so that shoulder 14b locks against boss 12e, will resist beingloosened by repeated back and forth rotation of rotary member 13 onanchor member 12. In operation, the pressure of spring 15 against washer16 maintains a slight:y clearance between the latter and shoulder 13g.When stud 14 is tightened as hereinbefore described it is relativelyfixed with respect to anchor member 12 so that the swinging of arms Aand AA with respect to each other causes relative movement at the rabbetjoint and also between stud head 14e and washer 16 and/0r lbetweenwasher 16 and rotary member 13.

It will be understood thatlateral opening 13d in transverse wall 13b maybe omitted when the axial proportions of rota-ry member 13 and the sizeof spring 15 permit locating transverse wall 13b above side opening 13eto enable clear passage of wiring W into arm AA.

Any suitable means capable of being secured manually may be provided forattaching stud 14 to anchor memjber 12. To this end, a modified form ofthe invention is shown in FIG. 6 as swivel joint coupling 21 whichcomprises a rotary member 13, spring 15 and washer 16 all similar to thecorresponding parts of swivel 11, and an anchor member 22 having acylindrical side wall 22a and a bottom wall 22!)` formed with an axialopening 22C through which the threaded end 24a of axial stud 24 extendsfor retention therein by a cap type hex nut 25. Stud 24 has a shoulder24b for engaging bottom wall 22h shoulder 24h being spaced apredetermined distance from head 24e to insure slight clearance ofwasher 16 on shoulder 13g in a manner similar to stud 14 in swivel 11.Hex nut 25 locks stud 24 against relative rotation. Coupling 21 isassembled in a manner as hereinbefore described with reference tocoupling 11, except thathex nut 25 may be tightened on threaded end 24awith the aid of a Wrench and screwdriver. Heads 14C and y24C may beprovided in non-circ-ular form, such as, square or hexagonal for wrenchtightening.

The improved swivel joint couplings herein disclosed are seen to achievethe several objects of the invention and to =be well adapted to meetconditions of practical use. As various possible embodiments might bemade in the above invention, and as various changes might be made in thedisclosed constructions, it is to be understood that all matters hereinset forth or shown in the accompanying drawing are to be interpreted asillustrative and not in a limiting sense.

Having thus described my invention, I claim -as new and desire to secureby Letters Patent:

` 1. A swivel joint coupling comprising a pair of hollow cylindricalmating members axially mounted in end-toend abutment at a friction jointtherebetween for relative rotation, an opening in the side `of eachmember for mounting a hollow arm therein, a first of said members havingan end wall closure and an opposite open end facing an open end of thesecond of said members -at said joint, said second member having asecond open end opposite said end wall closure formed with an interiorshoulder, a washer closing said second open end seated on said interiorshoulder, a headed stud extending axially through said washer andanchored to said first member end wall closure, an interior transversewall in said second member spaced from said washer and having an axialopening through which said stud extends, `and a compression springinterposed between said washer and interior transverse wall exertingfriction pressure between the members at said joint through said stud,said stud retaining said washer in position free of locking engagementwith said interior shoulder.

2. The swivel joint coupling defined in claim 1 in which said headedstud is formed with a threaded end of a reduced cross-section providinga shoulder, said first member end wall closure having an interior axialthreaded Iboss receiving said stud threaded end with said shoulder intight abutment thereto securing the stud against accidental rotationeffecting said anchoring, the spacing along said stud between saidshoulder and head being predetermnied for said washer retention free ofsaid locking engagement.

3. The swivel joint coupling defined in claim 1 in which said headedstud is formed with a threaded end of a reduced cross-section providinga shoulder, said first member end wall closure being formed with anaxial opening through which said threaded end extends, and a retainingnut threaded onto said end clamping said shoulderV against said end wallclosure for securing the stud against accidental rotational effectingsaid anchoring.

4. The swivel joint coupling dened in claim 1 in which said transversewall is aligned with said side opening and is formed with a lateralcutout adjacent said opening for -passage of electric wiringtherethrough.

No references cited.

LEWIS H. MYERS, Primary Examiner.

D. L. CLAY, Assistant Examiner.

1. A SWIVEL JOINT COUPLING COMPRISING A PAIR OF HOLLOW CYLINDRICALMATING MEMBERS AXIALLY MOUNTED IN END-TOEND ABUTMENT AT A FRICTION JOINTTHEREBETWEEN FOR RELATIVE ROTATION, AN OPENING IN THE SIDE OF EACHMEMBER FOR MOUNTING A HOLLOW ARM THEREIN, A FIRST OF SAID MEMBERS HAVINGAN ENDWALL CLOSURE AND AN OPPOSITE OPEN END FACING AN OPEN END OF THESECOND OF SAID MEMBERS AT SAID JOINT, SAID SECOND MEMBER HAVING A SECONDOPEN END OPPOSITE SAID END WALL CLOSURE FORMED WITH AN INTERIORSHOULDER, A WASHER CLOSING SAID SECOND OPEN END SEATED ON SAID INTERIORSHOULDER, A HEADED STUD EXTENDING AXIALLY THROUGH SAID WASHER ANDANCHORED TO SAID FIRST MEMBER END WALL